Catalytic activities of tungsten nitride for NO dissociation and reduction with hydrogen

C. Shi, X. F. Yang, A. M. Zhu, Chak Tong AU*

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

23 Citations (Scopus)

Abstract

Tungsten nitride (W2N) was synthesized from WO3 and NH3 by means of temperature-programmed nitridation, and its activities for NO dissociation as well as NO reduction with H2 were evaluated. In a 5% H2/1% NO/He stream at 400°C, stable NO conversion to N2 of ca. 82% was observed within a test period of 40h. When the H2/NO ratio was reduced to 3/1, the conversion was ca. 80% and the catalyst started to deactivate after 28h of on-steam time. At a H 2/NO ratio of 1/1, NO conversion to N2 was ca. 63% and such performance could last for only 23h; even in the absence of H2, a conversion of ca. 52% lasted for 22h. We applied the XRD and XPS techniques, respectively, to examine the structural and compositional changes of W 2N during the reactions. The results indicated that the gradual loss in catalytic activity was due to the bulk oxidation of W2N into WO3. Combined the activity measurements with those of NO adsorption studies, we deduce that W2N is catalytically active for NO adsorption and dissociation, and a H2/NO ratio of 5/1 is required to avoid heavy accumulation of surface oxygen and deactivation of the catalyst.

Original languageEnglish
Pages (from-to)819-826
Number of pages8
JournalCatalysis Today
Volume93-95
DOIs
Publication statusPublished - 1 Sep 2004
EventSelections from the Presentations of the 3rd Asia-Pacific Congress - Dalian, China
Duration: 12 Oct 200312 Oct 2003

Scopus Subject Areas

  • Catalysis
  • Chemistry(all)

User-Defined Keywords

  • NO dissociation
  • NO reduction
  • Tungsten nitride

Fingerprint

Dive into the research topics of 'Catalytic activities of tungsten nitride for NO dissociation and reduction with hydrogen'. Together they form a unique fingerprint.

Cite this